Xenbase Image ID: 153522

Figure 6. RA Is Required for Respiratory Competence of the Xenopus Foregut Endoderm (A) Endoderm explants dissected at NF22 were treated with Bio, BMP4, or Bio + BMP4 from NF25–38 and assayed by in situ hybridization with the indicated probes. Bio + Bmp4 induces nkx2-1/sftpc+ respiratory fate, but pre-treatment of embryos from NF14–22 with the pan-RAR antagonist BMS493 prevents respiratory induction and shh expression. BMP4 represses sox2 and induces the BMP-target gene id4, whereas Bio induces the Wnt-target gene cyclind1. (B) Endoderm isolated at NF14 is not competent to express nkx2-1 or sftpc in response to subsequent Bio + BMP4 treatment from NF25–38. However, after RA treatment of endoderm from NF14–25, nkx2-1/sftpc+ respiratory progenitors are induced in response to Wnt and BMP4 activation. Image published in: Rankin SA et al. (2016) Copyright © 2016. Image reproduced with permission of the publisher and the copyright holder. This is an Open Access article distributed under the terms of the Creative Commons Attribution License. Larger Image Printer Friendly View

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